John 3:4-6

Amplified Bible

⁴ Nicodemus said to Him, “How can a man be born when he is old? He cannot enter his mother’s womb a second time and be born, can he?” ⁵ Jesus answered, “I assure you and most solemnly say to you, unless one is born of water and the Spirit he cannot [ever] enter the kingdom of God.^{(A) 6} That which is born of the flesh is flesh [the physical is merely physical], and that which is born of the Spirit is spirit.